https://en.wikipedia.org/wiki/Wall
"Brick wall close-up view" by Pawel Wozniak - http://freestocktextures.com/texture/id/690. Licensed under CC BY-SA 3.0 via Commons - https://commons.wikimedia.org/wiki/File:Brick_wall_close-up_view.jpg#/media/File:Brick_wall_close-up_view.jpg
Defensive wall
Retaining wall
Tetrapod
'Excavations led to the discovery of huts that had been built from mammoth bones.
The huts date back 15,000 years, and are among the earliest known prehistoric shelters.'
